Farber S A, Bogdanov M, Marshall D L, Tehovnik E J
Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge 02139, USA.
J Neurosci Methods. 1997 Sep 5;76(1):93-104. doi: 10.1016/s0165-0270(97)00090-3.
The excitability of cholinergic, glutamatergic and dopaminergic elements within the rat neostriatum was studied in both in vivo and in vitro preparations. In vivo, the microdialysis technique was used to measure the release of striatal acetylcholine and dopamine under basal and electrically evoked conditions. For comparison, acetylcholine, dopamine and glutamate release was assayed in media obtained from superfused rat striatal slices. Electrical stimulation was used to derive the strength-duration functions and their chronaxies of stimulated elements containing the three neurotransmitter types. The chonaxies for experiments in vitro and in vivo were similar: the chronaxy values for elements containing acetylcholine were the shortest, the values for glutamate were intermediate, and the values for those containing dopamine were the longest. Based on the chronaxy estimates, it is proposed that the elements containing acetylcholine are the large cholinergic interneurons of striatum, and the elements containing glutamate and dopamine are the terminals of corticostriatal and nigrostriatal neurons, respectively. These results indicate that electrical stimulation of neural elements surrounding a microdialysis probe can be an additional tool to examine the factors that regulate neurotransmitter release. Likewise, investigators can activate specific striatal elements by using pulse durations that coincide with their chronaxies.
在体内和体外实验中研究了大鼠新纹状体内胆碱能、谷氨酸能和多巴胺能神经元的兴奋性。在体内，采用微透析技术测量基础状态下和电刺激诱发条件下纹状体乙酰胆碱和多巴胺的释放。作为对照，在从大鼠纹状体灌流切片获得的培养基中检测乙酰胆碱、多巴胺和谷氨酸的释放。通过电刺激得出含有这三种神经递质类型的受刺激神经元的强度-时间函数及其时值。体外和体内实验的时值相似：含乙酰胆碱的神经元时值最短，含谷氨酸的神经元时值居中，含多巴胺的神经元时值最长。根据时值估计，推测含乙酰胆碱的神经元是纹状体中的大型胆碱能中间神经元，含谷氨酸和多巴胺的神经元分别是皮质纹状体和黑质纹状体神经元的终末。这些结果表明，对微透析探针周围神经元进行电刺激可以作为一种额外的工具来研究调节神经递质释放的因素。同样，研究人员可以通过使用与时值一致的脉冲持续时间来激活特定的纹状体神经元。
